Quote:
Funny, I thought they were all 8 ohms, but Boston Acoustics web page lists some as 3 ohms. I'm sure the 8 used to be the standard years ago.


Well, there were at least 3 "standard" impedances, 4, 8 and 16 ohm. Old valve gear, with high voltages but low current drive capability, prefers high impedance - that's why the classic BBC 3/5A was 16 ohm. For car systems that work off 12V, lower impedances are better - but if you go too low, your cable resistance starts to influence things too much - the reason old whole-building PA/muzak systems used hundreds of ohms (and volts!).

Most modern hifi speakers are (nominally) between 4 and 8 ohm.